KR101729341B1 - Laser beam interleaving - Google Patents

Abstract

The laser system 511 includes a first source 519/2 and a second source 519/1 for generating a first laser beam 523/2 and a second laser beam 523/1, A first interleaved laser mirror 531/1 having a high reflection area configured to reflect one laser beam 523/2 and a first high transmission area configured to transmit the second laser beam 523/1 do.

Description

Laser Beam Interleaving < RTI ID = 0.0 >

The present invention relates to a beam forming unit, for example, for a high output diode laser system.

Laser systems for high performance solid state lasers can be based on laser diodes and laser diode bars. In order to provide a high pump output, for example, to a solid-state laser medium of a disc laser, the emitted laser beams of the multiple laser diode or laser diode bar are combined to form a pump laser beam.

The system disclosed herein provides a simple and cost effective way of combining, for example, a high output laser beam of a diode laser.

In some aspects, the laser system includes a first source and a second source that respectively generate a first laser beam and a second laser beam, a high reflection region configured to reflect the first laser beam, And a first interleaved laser mirror having a first high through-pass region configured to transmit light.

In another aspect, a laser system includes a first source and a second source that respectively generate a first laser beam and a second laser beam, and a mirror device including a first interleaved laser mirror and a first overtone region, The apparatus is configured such that the highly reflective region of the first interleaved laser mirror reflects the first laser beam and the first highly transparent region of the first interleaved laser mirror transmits the second laser beam.

In another aspect, there is provided a laser mirror for interleaving laser light of at least two sources, wherein the laser mirror includes at least two laser light sources for reflecting the laser light so as to propagate in a second direction, And at least two transmission areas for transmitting laser light propagating along the second direction toward the second surface of the laser mirror, wherein the reflection area and the transmission area alternate in the interleaving direction.

In another aspect, a method includes providing a first set of laser beams propagating in a first direction toward an interlaced laser mirror, deflecting the first set of laser beams into an interleaved laser mirror, Generating a beam, generating a second set of laser beams propagating in a second direction toward the interleaved laser mirror, and transmitting the second set of laser beams through the interleaved laser mirror to generate a transmitted laser beam Wherein the first set of laser beams is displaced in an interleaving direction, the interleaving direction is orthogonal to a first direction, the second set of laser beams are displaced in an interleaving direction, and the deflected laser beam is transmitted in an interleaving direction Lt; / RTI > laser beam.

In another aspect, a method includes interleaving a plurality of sets of laser beams in an interleaving direction, and pumping the laser medium into interleaved beams, wherein each set of laser beams is emitted from a source of a group of sources, Interleaved beam, and the adjacent laser beam in the beam corresponds to different sources of a group of sources.

Embodiments may include one or more of the following features.

The multiple reflective and transmissive regions of the laser mirror may alternate in the interleaving direction.

The overtransmissive region may be the first overtransmissive region, the laser mirror may be the second overtransmissive region, and the first overtransmissive region and the second overtransmissive region may be separated by the higher reflection region.

The high reflection region may be a first highly reflective region and the laser mirror may comprise a second highly reflective region, wherein the first highly reflective region and the second highly reflective region may be separated by a highly transmissive region.

The high transmittance region may be formed by a partially transmitting laser mirror or a through hole in a material / region that transmits a specific wavelength.

The first laser beam and the second laser beam may have a three-dimensional beam profile, and the high-reflection area and the high-transmit area may fit the elongated beam profile or another specified beam profile of the beam.

The mirror device may be configured to propagate toward the opposite side of the laser mirror through which the first and second laser beams partially pass.

The mirror device may be configured to align the first laser beam and the second laser beam in a first direction.

The first source and the second source may comprise laser diodes or laser diode bars that respectively generate a first laser beam and a second laser beam.

The first source and / or the second source may each include a plurality of laser diodes or laser diode bars that can be displaced pitch in the first direction. The pitch may be, for example, at least 5 mm, 10 mm or 15 mm. In some embodiments, the pitch may be at least as large as the cavity length of the laser diode or laser diode bar. In another embodiment, the pitch may also be less than the cavity length of the laser diode or laser diode bar.

The laser mirror can be positioned in the mirror device to vertically interleave multiple laser beams of the first and second sources.

The laser system may further include a mount, wherein the first source and the second source are mounted on the mount with offset in a first direction.

The laser system includes a third source for generating a third laser beam, a second interleaving laser having a high reflection region configured to reflect the first laser beam and a high transmission region configured to transmit the third laser beam, And may further include a mirror.

The laser system has a fourth source for generating a fourth laser beam, a high reflection region configured to reflect the fourth laser beam, and a high transmittance region configured to transmit the first laser beam, the second laser beam and the third laser beam And a third interleaving laser mirror.

The first source, the second source, and the mirror device may be arranged to provide substantially the same optical path length for the first and second laser beams.

Interleaved laser mirrors can provide high reflectivity for an incident angle of 45 degrees.

The first source may further comprise a heat sink and deflection optics. Furthermore, several laser diodes or laser diode bars of the first source may be arranged flat on the heat sink to emit a laser beam parallel to the heat sink, the fast axis being orthogonal to the stack direction of the laser beam.

The deflection optics may be configured to deflect the laser beam emitted in parallel to the heat sink in a direction perpendicular to the heat sink.

The heat sink can be electrically isolated from the laser diode or laser diode bar through the ceramic layer.

The laser system may further comprise a beam forming optic disposed in the optical path of the first and second laser beams after the mirror device.

The mirror device may further include two mirrors. The mirror device may include n sources and at least n-1 laser mirrors, where n is an integer.

The laser system may further comprise a beam forming optics comprising optics selected from the group consisting of a fast axis collimating optics, a slow axis collimating optics, a cylindrical optical telescope for adjusting the fast axis, and a folding mirror.

A laser diode or laser diode bar may be arranged to operate in a heat sink based on the current flowing in series through the laser diode or laser diode bar.

The laser system may further comprise a mount configured to mount a first source and a second source.

The transmissive region and the reflective region may be configured to transmit or reflect a laser beam having a narrow beam profile.

The interleaving laser mirror may be configured to transmit and / or reflect a laser beam having a narrow beam profile that may have a ratio of width to height of at least 2: 1, 5: 1, 10: 1 or more.

The laser mirror may be a metal mirror. The interleaving laser mirror may comprise a substrate and a high reflectivity coating on the substrate forming the reflective region. The at least two transmissive regions may be through-holes passing through the substrate.

The interleaved laser mirror may include an anti-reflection coating on the substrate to form a transmissive region.

In the interleaving direction, one of the at least two transmitting regions may be approximately the same as one of the at least two reflecting regions. The extension may, for example, be at least 5 mm.

The interleaved laser mirrors may have a ladder-like structure, the stages of the ladder-like structure corresponding to the reflection area and the space between the stages corresponding to the transmission area.

Interleaved laser mirrors can provide high reflectivity for non-orthogonal incidence angles, particularly angles of incidence of about 35 degrees, 40 degrees, 45 degrees 50 degrees, or 55 degrees.

An advantage of some embodiments is that it can improve, for example, maintenance capabilities (e.g., replacement of sources) by including simple mechanical devices that allow for easy mounting and mounting of sources that provide direct access to the individual sources.

Moreover, in some embodiments, laser light from a single source can contribute to various areas of the cross-section of the interleaved beam. Thus, the single function of a single source affects only the beam in the diffused area. Thus, the asymmetry effect on the beam, and thus on the pumped volume of the laser medium, for example in a laser pump beam application, can be reduced.

In some embodiments of a high power laser system, the source may provide the beam at a long distance to increase the cooling performance of the individual diode lasers. Specifically, in such a system, a larger "no radiation" region between (e.g., high power) laser beams can be filled with the laser beam from the remaining sources of the system.

The details of one or more embodiments of the invention are set forth in the following description and the accompanying drawings. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.

In accordance with the present invention, it is possible to improve, for example, maintenance capabilities (e.g., replacement of sources) by including a simple mechanical arrangement that permits easy alignment and mounting of sources that provide direct access to individual sources.

Figure 1 is a schematic block diagram of an optically pumped laser system using an interleaved beam.
Figure 2 is a schematic front view of the source.
FIG. 3 is a cross-sectional view of the interleaved beam shown in FIG. 1 taken along section III-III generated from the three sources shown in FIG.
4 is a schematic front view of a laser mirror.
Figure 5 is a perspective view of the implementation of a laser system that may be used in the laser system of Figure 1;
Figure 6 is a perspective view of the source and mirror structure of Figure 5 with the top and bottom plates of the mirror structure removed.
Figure 7 is a top view of the laser system of Figure 6;
FIG. 8 is a side view of the laser system of FIG. 6 along section VIII-VIII shown in FIG.
FIG. 9 is a side view of the laser system of FIG. 6 taken along section IX-IX shown in FIG.
Figure 10 is a side view of the laser system of Figure 6;
Figure 11 is a side view of an exemplary first source of the laser system of Figure 6;
12 is an enlarged cross-sectional view of the source according to cross-section XII-XII shown in Fig.
13 is an enlarged perspective view of the cross section XIII shown in Fig. 11 of the source of Fig. 11;
Figure 14 is a perspective view of an exemplary second source that can be used with the laser system shown in Figures 5 to 10;

A group of laser diodes or laser diode bars may be arranged to provide a spatially separated laser beam. Here, such a structure is referred to as a source of a spatially separated (stacked) laser beam. Thus, the source of the stacked laser beam emits several laser beams having similar beam parameters, i.e., slow axis and similar parameters for the fast axis. By combining the laser beams of multiple sources of stacked laser beams, it is possible to form a beam with a radiation higher than that for a single source of the stacked laser beam, i.e. to increase the output within a certain cross-sectional area of the beam. For example, a beam forming element suitable for forming the beam to permit efficient optical pumping of the laser medium may also be applied.

In Figure 1, an optically pumped laser system 1 provides a high power laser beam 3 to a laser processing system 5, such as a laser cutting system or a laser welding system. For example, the laser system 1 may be a solid state laser system, such as a disc laser system, which provides several kW laser beams to the laser processing system 5. Other exemplary laser systems may be fiber lasers. The laser medium 7 of the laser system 1 is optically pumped using the interleaved beam 9 generated by the laser system 11 in order to generate the laser beam 3. However, the laser system 11 may also be configured as an independent laser system used in laser applications such as surface treatment, curing, material processing and soldering.

The laser system 11 includes, for example, a plurality of sources mounted on a device 15, a mirror device 16, and a beam forming optics 17. The device 15 is configured to provide a group of laser beams 13 of a plurality of laser beams, and each laser beam is displaced along one dimension, which may be referred to as the interleaving direction 18. Mirror device 16 includes several interleaved laser mirrors forming an interleaved beam 9 by superimposing the laser beams of group 13 on top of each other. Beamforming optics 17 may comprise optics that collimate and homogenize the laser beam into the interleaved beam 9. The interleaved beam 9 is provided to the laser system 1 as a pump laser beam, for example directly or through a waveguide such as an optical fiber.

Fig. 2 schematically shows a source 19 which can be used in the device 15. Fig. Fig. 3 shows a cross section taken along III-III of the interleaved beam 9 of Fig. This cross section can be generated by the three sources 19 of Fig. Figure 4 schematically shows a laser mirror that may be used in mirror device 16. An embodiment of an interleaved laser system is described in detail, for example, with FIGS. 5 through 13, which can be used as the laser system 11 of FIG.

As shown in Figure 2, exemplary source 19 includes three laser diode bars 20 mounted on a common heat sink 21. Each laser diode bar 20 includes a semiconductor structure having five adjacent emission regions. The laser light in a single emission area has an elliptical beam profile 22. The elliptical shape of the beam profile 22 represents the different optical properties of the fast and slow axes of the laser beam. For example, the laser beam of the emission area emits more in the direction of the faster axis than the direction of the slower axis due to the thickness of the emission area.

The light in the five emission regions forms the laser beam 23 of the laser beam group 13, and each laser beam 23 has the elongated shape. In some embodiments, the emission area emits light orthogonal to the heat sink 21, but in other embodiments the light is emitted parallel to the heat sink 21 and then deflected, e.g., by 90 degrees.

In the interleaving direction 18, the three laser diode bars 20 are mutually displaced by the pitch P, so that the three laser beams 23 are also displaced by the pitch P. Therefore, the laser beam 23 emitted from the single source 19 forms a beam having its own cross-section, and this cross-section is formed between the region where the laser beam is displaced by the pitch P and the region where the laser beam is present And a region 29 in which no laser beam is present. Some high power sources provide laser beams of large pitches of several millimeters, e.g. at least 5 mm, 10 mm or 15 mm. Examples of such high power sources include a source (flat source) having a flat mounted laser diode bar as described in conjunction with FIGS. 11-13, a laser diode bar (group source) stacked as described in conjunction with FIG. 14, Lt; / RTI >

Interleaved laser systems can be particularly suited for use with sources with large pitches.

Figure 3 shows a simplified cross section along III-III of the interleaved beam 9 of Figure 1 based on three sources 19, each source 19 comprising three laser diode bars 20 And each laser diode bar 20 produces five laser beams 22 (as shown in FIG. 2). The laser system 11 is arranged to cause the light of adjacent rows of the beam to originate from a different source 19 in the cross-section of the interleaved beam 9 (for a total of nine laser beams in group 13) And interleaves the three laser beams 23 from each of the beams 20. Within the cross section, the single laser diode bar 20 contributes to the heat 24 in the cross-section shown through the elliptical beam profile 22 associated with the five emission regions of the laser diode bar 20.

In the example of FIG. 3, three rows of laser beams arise from each of the three sources 19. For example, the row 24 relates to the laser radiation A of the first source, the row 25 relates to the laser radiation B of the second source and the row 26 relates to the laser radiation of the third source C). Thus the area 29 without radiation between the emitted light of the laser diode bar 20 of each source 19 can be at least partially filled with the laser radiation originating from the two remaining sources 19 of the device 15. [ have. Thus, the laser radiation of the source 19 does not contribute to a single region of the cross-section of the interleaved beam 9, but contributes to different regions within the entire cross-section of the interleaved beam 9. The diffusion of such contributions to the cross section from each of the sources 19 is increased when the sources with a large number of laser diode bars are interleaved with each other.

Figure 4 shows a laser mirror 430 that may be used to partially reflect and partially transmit, e.g., interleave, the laser beam from three sources as shown in Figure 2. The laser mirror 430 includes a rectangular substrate 428. When mounted on the mirror device 16, the longer sides of the laser mirror 430 extend in the interleaving direction 18.

The laser mirror 430 is configured to interact with a series of laser beams directed by a slashed beam profile 423. A series of laser beams 423 includes three laser beams that originate from each source separated by a pitch P. The laser mirror 430 includes three transmission areas 429 in the form of through-holes, and each through-hole is formed to transmit two adjacent laser beams 423. The transmissive region 429 is generally at least partially transmissive. One side of the substrate is coated with a highly reflective coating 431 to provide a reflective region 432 between (and above and / or below) the through-holes. The reflective region has a size that reflects two adjacent laser beams 423. In other words, the laser mirror 430 has a ladder-like structure, the stages of the ladder-like structure correspond to the reflection region 432, and the space between the stages corresponds to the transmission region 429. The configuration and form of the laser mirror 430 is suitable for the device 15 having three sources 19. [ However, other configurations and configurations are possible and are dependent upon the number of sources 19 of device 15 and the relative size and location of source 19.

Therefore, depending on the relative position between the laser mirror 430 and the source in the interleaving direction, the laser beam 423 of the source is transmitted or reflected. Accordingly, the mirror device 16 is configured such that the laser beam from the first source and the laser beam from the second source are propagated toward the opposite side of the laser mirror 430, and the reflected laser beam and the transmitted laser beam are directed in the interleaving direction 18 The angle of incidence can be selected alternately.

In the mirror device 16, n-1 laser mirrors 430 can be arranged to interleave laser beams of n sources, where n is an integer. The transmissive region 429 and the reflective region 430 may be of a size that transmits or reflects a laser beam having at least a width-to-height ratio of, for example, 2: 1, 5: 1, 10: .

5-13, an exemplary interleaving laser system 511 is illustrated to illustrate the geometric interleaving of the laser beams 523 of the six sources 519. [ In an embodiment, each source 519 includes twelve laser diode bars that emit a laser beam that is spatially displaced by a pitch of 10 millimeters. However, similar interleaving can also be performed for more or fewer sources with smaller or larger pitches.

5 and 6, the laser system 511 includes a device 515 of six sources 519, five interleaved laser mirrors 530 / 1-530-5 and an upper plate 532, And a mirror device 516 including two bending mirrors 567 and 568 mounted between the bottom plate 533. [ The sources 519 are arranged to be arranged side by side and configured to emit a laser beam 423 in a first direction 534.

The laser system 511 includes a mirror device 516 to form a beam 509 that is displaced from the laser beam 523 in the interleaving direction 518. At the exit of mirror device 516, laser beam 523 is interleaved in the interleaving direction. Thus, the mirror device 516 redirects the incoming laser beam 523 in a common direction toward the first cylindrical lens 535 of the beam-forming optics 517.

5, beam-forming optics 517 includes a second cylindrical lens 536, a folding mirror 537, a beam mixer 538 and a collimating optics 539. In the embodiment of FIG. The first cylindrical lens 535 and the second cylindrical lens 536 form a telescope 540 that adjusts the beam parameters of the fast and slow axes of the laser beam 523. Thus, the beam forming optics 517 adjusts the various optical parameters of the interleaved beam 509.

Mirror device 516 is based on an interleaved laser mirror 530 optimized for reflection down to 45 degrees and includes a source of light 518 that is optimized for reflection down to 45 degrees to provide the same optical path length to laser beam 523 of various sources 519. [ 519 are located at the same distance in the first direction 534 and the second direction 541 (the second direction 541 is orthogonal to the first direction 534 and the interleaving direction 518).

Also, as described below in connection with FIG. 10, six sources 519 are identical and are mounted at different locations in the interleaving direction, such that each laser beam 523 is emitted at its own particular "interleaving" Thus, each laser beam 523 propagates parallel to the first direction 534 and the laser beam 523 is reflected or transmitted by the interleaved laser mirror as described in connection with FIGS. 6-9.

Further, FIG. 5 shows coolant connection 549 for cooling source 519. Coolant connection 549 is shown in FIG. The diagram of the interleaved laser system 511 shown in Figs. 6 and 7 shows the mirror device 516 with the top 532 and the bottom 533 removed. As described above, the apparatus 515 and the mirror apparatus 516 provide similar optical propagation for the laser beams 523 / 1-523 / 6. For example, the optical path length of each laser beam 523 to the cylinder lens 35 can be considered to be the same. The laser beam 523 then experiences approximately the same divergence in the interleaved laser system 511. [ The device 515 is configured to have the same source 519 with a pre-aligned emission angle, for example 90 degrees, to the front of the source 519. Each source 519 is mounted in a housing (not shown) of the interleaved laser system 511.

The housing includes an alignment pin for mounting the source 519 to the regeneration position. Thus, the source 519 can be replaced without rearranging the mirror device 516.

Figures 6 and 7 illustrate the position of 90 ° bending mirrors 567 and 568 and interleaving mirrors 530 / 1-5 positioned at 45 ° incident angles, which bend the laser beam 90 ° within mirror device 516, . The width of the interleaving mirror 530 / 1-5 corresponds to the width of the diverging laser beam 523, and the width increases as the interleaving mirror 530 / 1-5 is positioned closer to the lens 535, for example. Each interleaving mirror 530 / 1-5 includes as many reflective areas and as many transmitting areas as each source 519 emits laser beam 523. Thus, for example, if each source emits 12 laser beams 523, the interleaving mirror 530 has at least 12 reflection areas and 12 transmission areas. The reflective area and the transmissive area are interleaved in the interleaving direction 518.

In the mirror device 516, the interleaving mirror 530/1 emits the laser beam 523/1 emitted from the source 519/1 and reflected by the 90 ° bending mirror 567 to the interleaving mirror 530/1, Whereas the laser beam 523/2 emitted from the source 519/2 is positioned to be reflected by the interleaving mirror 530/1. Similarly, the interleaving mirror 530/2 transmits the laser beam 523/3 emitted from the source 519/3 through the interleaving mirror 530/2, while the laser beam 523/3 emitted from the source 519/4 is transmitted through the interleaving mirror 530/2. The laser beam 523/4 is positioned to be reflected by the interleaving mirror 530/2.

Furthermore, the interleaving mirror 530/3 is arranged so that after the interleaving mirror 530/2, the laser beam 523/3, 523/4 is transmitted through the interleaving mirror 530/3, The laser beam 523/5 emitted from the interfering mirror 530/3 is reflected by the interleaving mirror 530/3. Similarly, the interleaving mirror 530/4 is arranged such that the laser beam 523/1, 523/2 is reflected by the interleaving mirror 530/4 after the interleaving mirror 530/1, Is transmitted through the interleaving mirror 530/4.

Finally, the interleaving mirror 530/5 transmits the laser beams 523/3, 523/4, 523/6, while the laser beams 523/1, 523/2, 523/5 are transmitted through the interleaving mirror 530/5).

The diverging laser beam 523 and the interleaving mirror 530 / 1-5 are shown in the plan view of Fig. Figure 7 further illustrates the aspects of Figures 8 and 9.

FIG. 8 shows a cross section along the direction VIII-VIII shown in FIG. The variable positions of the sources 519/4, 519/5 and 519/6 in the interleaving direction 518 correspond to the laser beams 523/4, 523/5, and 523/6 having different positions in the interleaving direction 518, To the mirror device 516. If the positions of the reflection area and the transmission area of the interleaving laser mirror 530 / 3-5 are properly set, alignment of the laser beam 523 / 4-6 is allowed in the interleaving direction 518 alternately.

FIG. 9 shows a cross-sectional view of an interleaved laser system 511 along direction IX-IX shown in FIG. Between the 45 ° mirrors 567 and 568, the interleaving mirror 530 / 1-5 provides a reflective and transmissive region at various heights, so that the interleaving beam 509 (shown and described with respect to FIG. 3 (E.g., similar) twelve sets of alternating laser beams 523/16.

10, the same six sources 519 / 1-6 are attached to the upper portion 532 of the housing at positions 555 in the interleaving direction, respectively. The location can be defined, for example, by an alignment pin at the side wall of the housing, and the alignment pin is adapted to fit within the alignment hole 559 of the source 519 / 1-6. Thus, the laser beam 523 is emitted at a different position in the interleaving direction between the housing 532 and the housing bottom 533. A laser beam 523 (propagating at its own position in the interleaving direction) is incident on the last interleaving mirror (the laser beam 523/1, 523/2, 523/6) through which the laser beam 519/35 is reflected and the laser beam 523/1, 530/5). Thus, in the interleaved laser system 511, the individual laser beams 523 of all the sources are guided up and down such that the space free of the radiation of each source is at least partially filled with the laser beam of the remaining source 519.

For high power applications, a high power source such as that described in connection with Figs. 11-14 may be used for the device 515. Fig.

11 to 13, the flat source 1119 includes twelve laser diode bar units 1181, and each laser diode bar unit 1181 includes a laser diode bar 1120, a prism lens 1187 And an electrical connection 1150. As shown in FIG.

The diode laser bar 1120 is disposed on the flat surface of the monolithic rectangular heat sink 1121. Thus, the source 1119 can be said to be a flat source, and each laser diode bar 1120 can be efficiently cooled through a large area in thermal contact with the heat sink 1121. The generated heat is removed from the source by a coolant that is pumped through the heat sink 1121 through a coolant connection on the backside, for example, as shown in FIG. Mounting holes 1191 are disposed at each corner, and alignment holes 1159 are disposed at short sides of the rectangular heat sink 1121.

The twelve laser diode bars 1120 are disposed along the longitudinal direction 1137 of the rectangular heat sink 1121 disposed along the axial direction 537 in FIG. The heat sink 1121 has an insulating ceramic layer 1195 as an upper layer that electrically isolates the radar diode bar 1120 from the heat sink 1121. Each laser diode bar 1120 includes a semiconductor structure 1110 with an active region having multiple emission regions. Semiconductor structure 1110 is attached to p-contact 1130. An electrical connection, such as a wire bond, electrically connects the semiconductor structure 1110 to the n-contact 1170 and the n-contact 1170 is electrically connected to the p-contact of the adjacent diode laser unit. Thus, when operating source 1119, (identical) current flows in series through all laser diode bars 1120. In addition, the diode laser bar 1120 can be controlled by a chip element 1190, respectively.

Semiconductor structure 1110 has elongated emission surfaces 1112, e.g., 30-45 adjacent active regions uniformly distributed at a length of about 10 mm. Each discharge surface 1112 is oriented perpendicular to the heat sink 1121 and has a discharge direction along direction 1137. Thus, the laser diode bar 1120 emits the laser beam 1123 in substantially the same plane parallel to the flat surface 1124 of the heat sink 1121. Each laser beam 1123 has a elongated profile whose slow axis extends in the direction of extension of the emitting surface 1112 of the laser diode bar 1120 i.e. in a heat sink (as described above with respect to Figures 2 and 3) 1121, and the initial fast axis is oriented in a direction perpendicular to the flat surface 1124 of the heat sink 1121. [

The emitted laser beam 1123 is reflected internally by the prism lens 1187 and the beam exiting the prism lens 1187 is reflected by the heat sink 1121 along the direction orthogonal to the flat surface 1124 of the heat sink 1121. [ ). ≪ / RTI > Thus, after exiting the prism lens 1187, the fast axis of the laser beam 1123 is in the direction 1137 along the length of the heat sink 1121, and the slow axis of the laser diode bar 1120 is not changed 1139). Further, the prism lens 1187 collimates the laser beam 1123 which strongly emits in the direction of the fast axis. The orientation of the prism lens 1187 is fixed by a common glass mount 1199.

The flat source 1119 may have the following parameters. Each source 1119 can provide an output of about 1700 W based on twelve laser diode bars 1120. The width of the laser diode bar 1120 in the slow axis direction may be about 10 mm. The maximum angle divergence of the laser beam 1123 in the slow axis direction may be approximately 6 [deg.] - 10 [deg.]. Emission in the fast axis direction from the individual laser diode bars 1120 is achieved through the emission surface 1112 having a height of approximately 1 mu m. Initially, the laser beam 1123 has a maximum angle divergence of approximately 40 ° -70 °. Each laser beam 1123 emitted from each laser diode bar 1120 is collimated in the fast axis direction using a prism lens 1187. [ The collimated laser beam 1123 typically extends 0.6-1.2 mm in the fast axis direction. The maximum angle divergence of the collimated beam after passing through the prism lens is approximately 0.5 DEG -2 DEG in the fast axis direction. The quality of the prism lens 1187, the accuracy of the lens alignment, and the straightness of the laser diode bar 1120 determine the divergence angle.

Applying a planar source 1119 to the embodiment of the device 15 of Figures 5 to 10 allows the fast axis of the emitted laser beam 1123 to be applied to the flat source 1119 at an early stage, And is oriented in the orthogonal direction. After reflection in the prism lens 1187, the fast axis of the emitted laser beam 1123 is directed in the interleaving direction 518.

Referring again to the planar source 1119 of Figures 11-13, the pitch between the two emitted laser beams 1123 is about ten times greater than the size of the laser beam 1123 when exiting the prism lens 1187 . Thus, there is no laser radiation line at about 9/10 of the cross section of the beam of the flat source. For example, in the case of the mirror device 516, the portion without radiation in the cross-section may be filled with the laser beam 1123 from another flat source 1119.

An alternative high power source is shown in FIG. 14 in the form of a group source 1419, where a plurality of laser diode bar units 1481 are grouped together in a group source. In Figure 14, for example, a group source 14190 includes 12 laser diode bar units 1481 each including a laser diode bar 1420, a lens 1490 and an electrical connection. Each diode laser bar 1420 Is disposed on the surface of copper block 1430 and emits a laser beam through lens 1490 at front face 1440 of group source 1419. In the rear region of laser diode bar 1420, adjacent copper blocks 1430 Is maintained in intimate contact so that copper block 1430 can be cooled by a common coolant system.

The twelve laser diode bars 1420 are disposed along the longitudinal direction 1437 of the group source 1419. Each laser diode bar 1420 includes a semiconductor structure with an active region having multiple emission regions forming a elongated emission surface. Each emission surface is parallel to the front surface 1440 of the group source 1419 and has a emission direction that is perpendicular to the front surface 1440. Each laser beam has a three-dimensional beam profile whose slow axis is oriented in the direction of extension of the exit surface of the laser diode bar 1420 and the fast axis is oriented in direction 1437.

The lens 1490 collimates the laser beam that strongly emits in the direction of the fast axis. The orientation of the lens 1490 is fixed by an extension 1431 of the copper block 1430 or by a glass block attached to the copper block 1430.

The group source 1419 may have a beam parameter similar to the flat source 919.

With respect to the planar source 1119 of Figures 11-13, the pitch of the group source 1419 between the two emitted laser beams may be about 10 times larger than the size of the laser beam, for example, when leaving the lens 1490 . Thus, there is no laser radiation line at about 9/10 of the cross section of the beam of the group source 1419. Using device 15 and beam forming optics 17, portions without laser radiation can be filled by a laser beam from another group source 1419. [

In the described device 515 the source 1119 can also provide a high angle accuracy of fast axis alignment by extending the contact surface or contact point between the associated mount and the heat sink 1121 over the entire length of the source 1119 And therefore can be geometrically well aligned.

The described concepts may be used with more or fewer sources and interleaving laser mirrors in various configurations. The interleaving laser mirror 530 may have a reflective coating suitable for a particular angle of incidence of the laser beam 523. Alternatively, some or all of the accompanying mirrors may be metal mirrors (e.g., with a silver coating). The reflective coating can be applied to a transmissive or non-transmissive substrate made of, for example, a glass or quartz substrate. In the case of a transmissive substrate, a modification to the above-described through-hole embodiment includes a transmissive region where the antireflective coating is coated or uncoated.

In some embodiments, the reflectance and transmittance of light is at least 80%, 85%, 90%, 95%, 98%, 99% or 99.8%. In addition to or alternatively to an angle of incidence of 45 [deg.], The mirror device includes interleaved laser mirrors designed for other angles of incidence including 35 [deg.], 40 [deg.], 50 [

Additionally or alternatively, the laser system 11 may include a folding mirror that provides a more compact telescope and / or collimating optical system within the beam forming optics 17. For example, a cylindrical mirror can be used as a folding mirror. Additionally or alternatively, in the beam-forming optics 17, the collimation of the slow axis and / or the fast axis can be achieved by one of a cylindrical lens, a flat mirror, a parabolic mirror, a parabolic folding mirror and a lens with a concave parabolic- Or more.

As shown in Fig. 1, in the optical beam path before the optical fiber or laser medium, additional optical components can be used to adapt and improve various beam parameters, such as beam divergence, smoothness of the beam profile, and the like.

Accordingly, other embodiments are within the scope of the following claims.

Claims (26)

As a laser system,
A first source and a second source for respectively generating a first laser beam and a second laser beam,
And a first interleaved laser mirror having a high reflection area configured to reflect the first laser beam and a first high transmission area configured to transmit the second laser beam,
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Wherein the mirror device is configured to align the first laser beam and the second laser beam in a first direction,
Wherein the first interleaved laser mirror has at least two reflection areas on a first surface of a laser mirror for reflecting laser light so as to be incident from a first direction and propagating in a second direction, At least two transmissive areas for transmitting laser light propagating along the direction, the reflective area and the transmissive area alternating in the interleaving direction,
Wherein the first interleaving laser mirror comprises a substrate,
Wherein at least one of the two transmissive regions is a through hole through the substrate. 2. The laser system of claim 1, wherein the plurality of reflective areas and transmissive areas of the first interleaved laser mirror alternate in the interleaving direction. 2. The laser system according to claim 1, wherein said high through area is a first high through area and said first interleaved laser mirror is a second high through area and said first high through area and said second high through area are separated by a high reflection area. . 2. The apparatus of claim 1, wherein the high reflection area is a first high reflection area and the first interleaving laser mirror comprises a second high reflection area, wherein the first high reflection area and the second high reflection area are separated . 2. The laser system according to claim 1, wherein the mirror device is configured such that the first and second laser beams propagate toward opposite sides of the first interleaved laser mirror. delete 2. The laser system of claim 1, wherein the first source and the second source each comprise at least one laser diode or laser diode bar that generates a first laser beam and a second laser beam, respectively. 2. The laser system of claim 1, wherein the first source and the second source each comprise a plurality of laser diodes or laser diode bars that are displaced pitch in a first direction. The laser system of claim 1, further comprising a mount, wherein the first source and the second source are mounted on the mount with offset in a first direction. 2. The apparatus of claim 1, further comprising: a third source for generating a third laser beam; a second source for generating a second laser beam having a high transmittance region configured to reflect the first laser beam and a high transmittance region configured to transmit a third laser beam; 2 interleaved laser mirror. 2. The laser system of claim 1, wherein the first source and second source and mirror devices are arranged to provide substantially the same optical path length for the first and second laser beams. The laser system of claim 1, further comprising a beam-forming optic disposed in an optical path of the first and second laser beams after the mirror device. 2. The laser system of claim 1, wherein the mirror device comprises n sources and at least n-1 interleaved laser mirrors, where n is an integer. The laser system of claim 1, further comprising a beam forming optics comprising optics selected from the group consisting of a fast axis collimating optics, a slow axis collimating optics, a cylindrical optical telescope for adjusting the fast axis, and a folding mirror . The laser system of claim 1, further comprising a mount configured to mount a first source and a second source. A laser mirror for interleaving laser light of at least two sources,
At least two reflection areas on a first surface of a laser mirror for reflecting the laser light so as to be incident from the first direction and propagating in the second direction,
At least two transmission areas for transmitting laser light propagating along a second direction toward a second surface of the laser mirror
Wherein the reflective area and the transmissive area alternate in the interleaving direction,
Wherein the laser mirror is configured to align the laser light in a first direction,
Wherein the laser mirror comprises a substrate,
Wherein at least one of the two transmissive regions is a through hole through the substrate. 17. The laser mirror of claim 16, wherein the transmissive region and the reflective region are configured to transmit or reflect a laser beam having a long beam profile. 17. The laser mirror according to claim 16, wherein the laser mirror is a metal mirror. delete 17. The laser mirror of claim 16, wherein the laser mirror comprises a high reflectivity coating on the substrate to form a reflective region. delete 17. The laser mirror of claim 16, wherein the laser mirror comprises an anti-reflection coating on the substrate to form at least one of the transmissive regions. 17. The laser mirror according to claim 16, wherein the laser mirror has a ladder-like structure, the stages of the ladder-like structure correspond to the reflection region, and the space between the stages corresponds to the transmission region. Providing a first set of laser beams propagating in a first direction toward an interleaved laser mirror;
Generating a deflected laser beam propagating in a second direction by deflecting the first set of laser beams to an interleaved laser mirror;
Providing a second set of laser beams propagating in a second direction toward the interleaved laser mirror; And
Generating a transmitted laser beam by transmitting the second set of laser beams through a through hole on a substrate of an interleaving laser mirror
Wherein the first set of laser beams are displaced in an interleaving direction, the interleaving direction is orthogonal to a first direction, the second set of laser beams are displaced in an interleaving direction, and the deflected laser beam is in an interleaving direction Is interleaved by a laser beam transmitted at a first wavelength. Interleaving a plurality of sets of laser beams in an interleaving direction, wherein one set of laser beams comprises a plurality of laser beams and is emitted from one of the plurality of sources to generate an interleaved beam Wherein adjacent laser beams in the interleaved beam are generated from different ones of the plurality of sources,
Interleaving the plurality of sets of laser beams includes deflecting the first set of laser beams to an interleaving laser mirror and transmitting the second set of laser beams through the through holes on the substrate of the interleaving laser mirror ,
Each set of laser beams being aligned in a first direction. 26. The method of claim 25, further comprising pumping the laser medium into an interleaved pump beam.

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